Management of Cough and Sore Throat in Patients with Mechanical Valve Replacement

Diagnostic Approach

The American Heart Association recommends that patients with mechanical valve replacement and respiratory symptoms be evaluated immediately for prosthetic valve endocarditis (PVE), as it can present insidiously with a mortality rate of 50-80% if not promptly diagnosed and treated 1, 2
Obtain at least 2 sets of blood cultures from different sites before administering any antibiotics, as blood cultures should never be delayed in patients with prosthetic valves who present with any unexplained symptoms 1, 2
The European Society of Cardiology suggests that the absence of fever does not exclude PVE, and valve thrombosis and endocarditis can present with subtle symptoms including increased shortness of breath, fatigue, or upper respiratory complaints 3

The American College of Cardiology recommends obtaining transthoracic echocardiography (TTE) urgently, with a low threshold for transesophageal echocardiography (TEE), as TEE detects vegetations in >95% of PVE cases compared to 60-75% with TTE alone 1, 2
Look specifically for new valvular regurgitation, paravalvular abscess, prosthetic valve dehiscence, vegetations, or valve obstruction on echocardiography 3, 2

Patients with mechanical valve replacement at 3 years post-surgery are in the "late-onset PVE" category, where Staphylococcus aureus and coagulase-negative Staphylococcus remain important pathogens 2, 4
PVE should be suspected in any patient with a prosthetic valve presenting with recent increase in shortness of breath, fatigue, or respiratory symptoms, with a higher suspicion if there has been recent subtherapeutic anticoagulation, dehydration, or infection 3

If blood cultures are positive or there is high clinical suspicion for PVE, transfer the patient to a cardiac center with cardiac surgical capabilities and administer empiric antibiotic therapy covering Staphylococcus, Streptococcus, and HACEK organisms 3, 5, 1, 2
The American College of Cardiology recommends vancomycin 30 mg/kg/day IV in 2 divided doses PLUS gentamicin 3 mg/kg/day IV in 3 divided doses PLUS cefepime 6g/day IV in 3 divided doses for empiric therapy 5
Surgical indications include heart failure, prosthetic valve dehiscence, evidence of increasing obstruction or worsening regurgitation, complications such as abscess formation, and infection with S. aureus, fungal, or highly resistant organisms 5, 4

If PVE is excluded, continue routine annual follow-up with complete history and physical examination, maintain therapeutic anticoagulation with frequent INR monitoring, and ensure the patient understands warning signs requiring immediate evaluation 7, 8, 6, 3, 1
Annual echocardiography is not routinely required if the patient is stable and asymptomatic, but it should be obtained if any new symptoms develop 6